Question 209812
There  is  a THEOREM,,,,"  If  two  angles  are  supplements  of  congruent  angles(or  the  same angle),  THEN  the  two  angles  are  congruent.
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In  this  case,,,the  "same  angle"  is 90 degrees.
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Both  of  the  right angles are  supplements,
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Therefore the  right  angles  are  congruent,
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Or    an  alternate  approach
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Definition of  a  right  angle  is " Angle  with  measure 90 degrees"
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Definition  of  congruent  angle  is "Angles  that  have  equal  measure"
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Since  both  angles  are  "right" ,  then  both  have  measure  of  90, therefore they  are  congruent.
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